<!DOCTYPE html>
<html>
	<head>
		<meta  charset="UTF-8">
		<title>51</title>
	</head>
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	<script>
var _hmt = _hmt || [];
(function() {
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  hm.src = "https://hm.baidu.com/hm.js?04e828ac441acffeb4a6bc5698f79d55";
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	<body>
		<script>
			function p(pwd){
			var z=!isNAN(pwd)&&pwd.toString().length==4;
			return z;
			}
			alert(p(1234));
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</html>
